This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. There haven't been any chapters recently, but it looks like there are a bunch in the pipeline and the old thread is nearing 700 comments. The latest chapter as of 7th March 2012 is Ch. 77.

As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.

Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically:

You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).

If there is evidence for X in MOR and/or canon then it's fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that "Eliezer said X is true" unless you use rot13.

I see also that the theories about Santa Claus's identity are equally as varied as the ones about Mr. Hat & Cloak. My take on this is similar to my take on H&C: we're meant to understand that Santa Claus is simply Dumbledore.

Santa Claus had possession of the Cloak of Invisibility and passed it down to Harry, who Santa somehow knew was its rightful heir.

Santa Claus also somehow knows about the full misdeeds of James Potter, many of which are known to no one else.

Santa Claus has the political and magical power to create Portkeys on the Hogwarts grounds and get away with it.

Santa Claus has deep insight into Dumbledore's true motives, and makes true statements about him without ever stating that Dumbledore is a different person.

Santa Claus knows little about Quirrell, but doesn't trust him.

Santa Claus says that he cares about Harry Potter's well being and wants him to be more careful in the future.

The only person we know for whom all the above facts are true is Dumbledore.

However, the "S" who left notes for Hermione is not Santa Claus. It's Severus Snape, who we know for a fact was the mysterious person helping SPHEW in its mission. The two signatures happen to both begin with S, but that's a coincidence; if the writer had intended Harry and Hermione to figure out that the two note senders were the same, they would have signed the letters to Hermione "Santa Claus" or at least "SC". Therefore, "S" doesn't know about the first notes and was not trying to connect his notes to them.

Let me add to my previous hypotheses about Eliezer's state of mind while writing: The fact that something is entirely mysterious to the characters does not mean that it's supposed to be entirely mysterious to us. We are certainly meant to know that "S" is Snape. We know this because of Interlude with the Confessor. It could not be any more blatant without being stated in the Author's Notes.

I equally believe that we're meant to know that "Santa Claus" is Dumbledore. Everything in the Santa Claus notes is entirely 100% consistent with what we know of Dumbledore and his character from canon and from MoR. Likewise, the fact that Mr. Hat and Cloak is entirely mysterious to Zabini and Hermione does not mean that we are supposed to reach deep into the implausible for explanations.

Certainly I could be wrong about any of this. The simple answer is not always the best answer. But all other things being equal, it's a good bet. And the evidence for these "simple" explanations is at least equal to the evidence that, say, Hat and Cloak is a manifestation of Voldemort's essence that leaves Quirrell's body for unknown reasons.

Sirius Black fits Santa as well, if not better, though most of what we know about Sirius comes from Cannon.

In Cannon Dumbledore had possession of The Invisibility Cloak when the Potters were killed, but he didn't necessarily keep it. This wasn't mentioned in books 1-5 though, so EY is probably unaware of that detail.

James' best friend Sirius knows James' misdeeds better than anyone besides James himself, and is much more likely to speak proudly of them than Dumbledore.

The Portkey doesn't have to have been made by Santa - it could have been made by anyone at the Salem Witches' Institute. And it doesn't work on the Hogwarts grounds.

Santa Claus claimed Dumbledore would keep The Invisibility Cloak if he ever got his hands on it, which was completely wrong, and a rather insane thing to say if it's Dumbledore (which doesn't prevent it from being Dumbledore, but still...)

Sirius wouldn't know anything about Quirrell. Dumbledore presumably researched him before offering him the DA job. Neither would trust him.

Sirius Black is a major fixture of Harry Potter canon. He has not yet been featured or brushed off yet (eg the Weasleys). Every other major player from the first books has been given screentime so far. It seems incredibly unlikely for Sirius to make it to chapter 78 without a showing in one form or another.

I am pretty sure Santa is someone who works / lives in Hogwarts. Outsiders are not supposed to enter on their own.

The bit about not trusting Dumbledore makes sense, even if the cloak came from him, since it allows Dumbledore to show off how trustworthy he is with little effort. And he can check how well Harry can keep a secret.

The line about having been sorted into Ravenclaw could be as fake as the Fuyuki City thing, Scrimgeour's play. Quirrell's apparent failure could just be a way of getting temporarily detained, while Dumbedore's looking for Riddle and Harry wants his help. His cover could actually be pretty solid, so he'd just shrug off Scrimgeour's suspicions once it's time to go.

Speculation on the Slytherin/Ravenclaw issue: Quirrell is a double impostor. He's Voldemort possessing a Slytherin (name unknown) and pretending to be that Slytherin pretending to be a Ravenclaw named Quirinus Quirrell. Dumbledore knows about one level of the masquerade, and accepts the explanation that the Slytherin of unknown name is a private person. Quirinus Quirrell may be an entirely constructed identity, although that would make it less likely for him to have failed to remember some of the details of it under interrogation.

Ch 78
You know, of all the things in the chapter, the law of Potion-Making seems the most important, by far - if I understand it correctly, it has staggering implications.

It's clear that you can extract more than purely physical processes from ingredients - since we have potions that bestow even entirely abstract concepts like luck(and canon!Snape claimed to be capable of brewing fame and glory, I'm unsure if MoR!Snape claimed the same).

So, could you, say, take a CD with some software on it and use it as a Potions ingredient in order to extract the mental work that went into programming that software, creating a Potion of Excellent Programming or something? Or, even better - could you take a copy of some brilliant scientific research paper, extract the brilliant scientific genius out of it and use the resulting Potion in order to create an even more brilliant scientific breakthrough? That's godhood in one shot right there.

I also have to wonder how Potion-Making interacts with the Mind Projection Fallacy. If you use a video game as an ingredient, can you create a Potion of Fun out of the video game or no? Fun isn't an inherent property of video games, it's in the minds of the players.

You can make copies of books and of software CDs very cheaply. Given a law of conservation, it can't be the case that destroying (sacrificing) a cheap copy would gain you powerful results, or else you could generate infinite resources very quickly (and wizards would realize this).

Maybe destroying the last extant copy of a software would achieve the effect. One wonders what great magic was fueled by the burning of the Library of Alexandria.

True, using copies to achieve that kind of power doesn't seem to make much sense - the law even says that you can get as much... let's call it "work" out of the ingredient as was "invested". It's true that there isn't much of an investment of resources in copies.

So, forget the copies, let's use the originals.

For example, could you take Einstein's original notes/notebooks(copying them beforehand, of course, so that you don't lose information), liquefy them into a Scientific Breakthrough Potion and use that Potion to quickly figure another brilliant breakthrough? That's the kind of thing I'm wondering about.

If this were the case, could Hermione sacrifice the paper marked 42 for a Potion of Humanism?

Or if Harry wrote down his thesis on Partial Transfiguration, Hermione could make a potion from that (without reading it), and write down whatever discovery she made under the influence of the Breaking the Laws of Magic Potion, which Harry could then use to make a potion...

No, because the notebooks do not "contain" the work Einstein did, Einstein's brain contains it. So you'd need the living brain of a scientist as brilliant as Einstein. Which may not be that difficult; Einstein was good but he was also lucky - he glommed onto exactly the right Big Problem at exactly the right time. It's quite possible that there are any number of equally-brilliant scientists alive today who just happened never to find their Big Problem. The point remains, however, that paper and notebooks are not sufficient, you need the brain which actually contains the comprehension.

Moreover, since magic works by sensible-to-humans laws in the MoRverse, even if you copied the brain you'd have to use the original in the potion, and you only have one of those. The reason being, the copy hasn't "done the work" even though it contains the comprehension; and you can only get back out the work that was put in. This of course makes no sense, information should be information, but the laws of magic were apparently designed by a human.

So you'd need the living brain of a scientist as brilliant as Einstein.

Not necessary living. And Einstein's brain just happens to be preserved.

In fact, it sounds very much like people quarreled over magical ingridients:

Harvey then removed, weighted and dissected into several pieces Einstein's brain; some of the pieces he kept to himself while others were given to leading pathologists. [....] Harvey also removed Einstein's eyes, and gave them to Henry Abrams.[2] He was fired from his position at Princeton Hospital shortly thereafter for refusing to relinquish the organs.

Another thought: write down a description of a complex magical principle that you understand, but that the interdict of merlin would prevent someone else who was reading it from understanding. Use the parchment you wrote on as an ingredient in a potion to make a potion with the mental work needed to discover/comprehend that principle.

Poof, Interdict of Merlin loses its teeth entirely. :)

Another thought that occurred to me: Felix Felicis. No wonder it's hard to brew. Only way you could brew it is if you literally got lucky in the process of brewing it, by chance, so that you can take that "chance" and put it into the potion.

(hrm... might be able to automate the process of making Felix: Have a machine that keeps mixing the ingredients many times in parallel, ie, many "potential potions", and in the process does something like for each potential potion, has a coin (or some random bit source which can then be physically placed in the potion) which it flips a 100 times. It also tracks the results, and when one of the coins comes up all heads, it drops it into the candidate potion then calls up the wizard to complete the potion.)

Oh, and MoR!Snape did claim you could brew fame and stuff. That was one of the things MoR!Harry challenged him on, saying something like "How does that work anyways? You drink it and turn into a celebrity?"

Or, wait, an even more recursive version of your science power potion:

Make a clever potion. Use that potion as an ingredient in a potion to extract the mental work of creating a clever potion.

Make a clever potion. Use that potion as an ingredient in a potion to extract the mental work of creating a clever potion.

Entertainingly, precisely this trick can be used in Morrowind to beat what is meant to be a 20-40 hour game in a matter of minutes. Global victory condition, indeed.

I have to imagine there is no "clever potion" in MoR, though, because otherwise Harry would have seized on it instantly. It's too much like the recursive self-improvement we look for in AIs for Eliezer or Harry to have missed this possibility.

Hee hee. But no, I didn't mean a "potion of cleverness", I simply mean "be clever and invent a potion. Then use that potion as an ingredient to place the quality of the mental work of inventing a potion into a potion... then use that potion as an ingredient, etc.."

And actually, we know Harry meant to investigate mental magic, but we're not sure if he ever got around to it. (And, of course, there is Rowena's Diadem, which would seem to be an intelligence augmentation device. If that's in MoR, Harry's got to do something with it at some point. (But then, harry hasn't yet really jumped onto the existence of the Philosopher's Stone, so... well, I guess everyone here's already waiting for when he notices that and Epic Rages at the wizarding world along the lines of "you mean you already know how... you... ARGH!")

On the topic of potion invention, what ever happened to the cloak from the dementor Harry killed? Based on the rules of potions given so far, that could probably make a nice Potion of the True Patronus™.

I'd imagine that would be determined by the other ingredients and stirring patterns. It could also be used to make someone invisible to dementors, immune to the effects of dementors, temporarily unkillable, give off their own dementor-like aura, or just look like a dementor. Depending on what the other rules are, that cloak could be very valuable.

This thread is a little silly, even by local standards. First of all, the fact that a potion can be no stronger than its ingredients doesn't imply that a potion will always be as strong as its ingredients -- there are probably all kinds of other restrictions on what can be effectively brewed. By way of analogy, most Volvo engines don't run at Carnot efficiencies and most split pea soups don't run at more than 0.01 efficiency.

Second, all of the canon/fanon magical ingredients are non-copiable...a feather or a squished animal is not like a CD or a video game or a piece of parchment. Perhaps you could use the original of a piece of parchment if you didn't keep a spare copy, but EV drops lots of clues -- potion conservation was apparently designed by someone who thought the universe was fair, potion brewing is a substitute for a small, safe sacrifice, etc. -- everyone who's trying to figure out how to make a potion out of costless intellectual property is playing a different game than the one Harry's playing.

Third, advanced electronics tend to malfunction in proximity to strong magical auras -- so far the most advanced Muggle artifact that's been successfully used to interact with wizards are a car battery and a solid-fuel rocket -- both of which basically just discharged their stored energy, without any controls more subtle than an "on" button.

Fourth, would it really be fun if Harry put Science into a cauldron and took out a flask full of Win? A major theme in the fanon so far is the importance of working together in teams and coalitions. Harry already has enough power to singlehandedly overcome most casual bands of students. He destroys Dementors, outwits Headmasters, is fabulously wealthy, incredibly famous, has above-average magical strength, bloody single-minded discipline & determination, and of course an excellent background in basic cognitive science. If he suddenly became an expert programmer, researcher, etc. and broke Merlin's Interdict, he'd have enough power to singlehandedly overwhelm adult powerhouses like Lucius or Flitwick...I don't buy it. I predict that Harry will be prompted to learn how to play politics on a national scale, just as Harry has recently learned how to lead teams on a school-wide scale.

I figure being referenced in the author's notes is enough to justify cross posting. I guess I'll find out if that's the case. (In the choice between not posting and posting without updating speculation, I decided to rationalize my sloth with a false dichotomy, maybe.)

pervenit pasta

Chapter 14: The Unknown and the Unknowable

HJPEV tells McGonagall about the message for Slytherin's Heir, refuses point-based reward, receives Time Turner, freaks the fuck out about receiving a time machine to treat his sleep disorder, has another 'you turned into a cat' moment, receives invisibility cloak from unknown person, learns what getting lost in Hogwarts entails, pranks himself, learns "There was something wrong with Harry Potter."

Chapter 21: Rationalization

Hermione deludes herself about why she likes beating HJPEV, chooses love, displays knowledge of Planning Fallacy, claims her prize; HJPEV creeps it up with Draco, claims Hermione as his own, traps Draco with promises of power, mentions that Draco should test the strength of muggleborn magic personally, agrees that human sacrifice is easier than changing his mind, establishes tradition of secrecy in the magical sciences, establishes Bayesian Conspiracy, receives a book, advice, and petty cash from 'Santa Claus,' receives 12-candle cake from twins, hears "HE COMES-' prophecy, summarizes the first 21 chapters for us, and writes home.

Chapter 26: Noticing Confusion

Quirrell dishes a Take That on cannon, lowers room temperatures, thoughtfully tortures inkwell to death, concedes that remedial education for mugleborn students is worthwhile damage control, and is cheered up; HJPEV learns the results of his proxy-prank on Rita Skeeter, is permitted to see uncommon expressions on Quirrell's face, takes a papercut that this reader once thought might have left Quirrell with a drop of his blood, becomes frustrated when Quirrell claims to have figured the prank out and refuses to share, is thwarted and dismayed at the bank, realizes what he did to Skeeter, is forced to say some things contrary to his good nature, and receives Roger Bacon's stolen diary; Quirrell foreshadows knowing where the Resurrection Stone is and kills Skeeter.

Chapter 35: Coordination Problems

HJPEV stares down Quirrell in a dispute over government models, Blaise Zabini meets Quirrel's eyes, while lying, while possessing knowledge of Mr. Hat-and-Cloak, and tells Quirrell and the hidden HJPEV that Dumbledore sent bullies after his cousin; Quirrell sells the story of Dumbledore's plotting and tells HJPEV that Dumbledore is "insane pretending to be sane pretending to be insane," then telegraphs his additional meeting to the reader; HJPEV demonstrates a preference for Heroic Sacrifice and shows the reader his allegiance to the muggles, not the magic; Mr. Hat-and-Cloak checks in on Blaise, uses the phrase "Salazar Slytherin would have keyed his monster into the ancient wards at a higher level than the Headmaster himself" which is almost repeated by Quirrell in chapter 49, "some entity which Salazar Slytherin keyed into his wards at a higher level than the Headmaster himself," and wipes himself from Blaise's memories; McGonagall tries to talk to Hermione about reasonable safety concerns and what good girls should be up to, fails; HJPEV uses ham-fisted reverse psychology on Draco, succeeds, and confesses his unnatural love for Quirrell.

Chapter 40: Pretending to be Wise

Quirrell lectures HJPEV on becoming vulnerable to Let's You And Him Fight (which is tragically a trope that diverges from the original meaning of the phrase and so is not linked here), answers some questions about the afterlife, lowers room temperatures, makes a joke with two of his favorite words as the punchline, learns that he already knows where the Resurrection Stone is (despite having justtold HJPEV that he should be careful when sharing information), drops a hint regarding his (modestly successful) quest for immortality, and runs off to steal a Deathly Hallow which he has almost certainly possessed since that very afternoon.

Chapter 43-47: Humanism & Personhood Theory

Dumbledore thinks Dementor Day is part of a cunning plan; Quirrell can teach AK to students who ask; Hermione and HJPEV want to Patronus, but cannot, and so they both embarass themselves and logically enough end up kissing after HJPEV experiences a memory a human brain could not contain and explores Utilitarianism; HJPEV explains his position on death, symbolically kills it while the author reveals the nature of Dementors, then refuses to tell anyone else how it's done; Quirrell punningly says that he does not mind being called a Death Eater, which is surprising considering what he did to the last person we know of who made that accusation, identifies Dumbledore as the most attractive target in all of Hogwarts, calls HJPEV on Confirmation Bias, and elicits a Top Five Hiding Places list from HJPEV, which turns out to be 'riddle' of some sort (or just another opportunity to pun his name in); HJPEV sends Hermione a How To (Symbolically) Defeat Death pamphlet, and figures some things out about his "I Was an Infant Honeypot" origin story, or so he thinks; Draco Patronuses, realizes that HJPEV is a Slytherin, hears about the insidious evils of discrimination, tells HJPEV about Dumbledore's evil deeds, the two boys talk about their dead mothers and bond under starlight; snakes briefly appear sentient

HJPEV lies to McGonagall; Dumbledore's Patronus can hunt; HJPEV dominates Bella, his dark side, his invisibility cloak, and a handful of Dementors, he hides from Dumbledore and transfigures some impressive things

Chapter 63: The Stanford Prison Experiment, Aftermaths

HJPEV & Hermione talk about what Phoenixes are for; HJPEV trusts Draco with a letter form Lucius; Neville does not get the support he might have expected from HJPEV in his proposed vengeance on Bella; Lesath Lestrange pledges himself to HJPEV, fails; Amelia Bones learns that someone was looking out for her people, draws the wrong conclusions in entirely an understandable fashion; Dumbledore tells the twins not to let HJPEV out of Hogwarts for any reason, appears successful; Moody supplies some of the best not-quite internal monologue in the whole fic while he and Snape punk the wrong bones; HJPEV muses on the nature and consequences of dishonesty and other depressing things related to human nature, then gets all mortal and human with Hermione, but not that way; Santa Claus strikes again; Sybill Trelawney speaks prophesies we are not told.

Chapter 66: Self Actualization

HJPEV cares about what Draco and Hermione think of him, tells Quirrell so; Hermione hears that HJPEV and Neville have been hanging with Edward and learning to be hardcore; HJPEV and Neville are hanging with Edward and learning to be hardcore.

Chapter 73-77: Self Actualization and Sunk Costs

It's an adventure. Lots of things happen. It's all too close to be sure of what parts are hints about what, except for Mr. Hat-and-Cloak, who we are to understand is most certainly Quirrell, hitting Hermione with a dictionary attack and turning her into someone less useful to HJPEV, I guess.

14

time travel

unknown ex-cloak-possessor who says the cloak itself wanted to return to HJPEV and references history repeating itself

what is wrong with HJPEV

21

Hermione rationalizes

HJPEV claims Hermione in front of Draco and threatens harm to any who'd do her harm

The Aurors swept toward him with swift strides, Auror Goryanof approaching from the other side of the Ravenclaw as though to block any escape...

Actual speculation: what did Dumbledore know or suspect when he hired Quirrell?

"If you consult Headmaster Dumbledore," said the Defense Professor, "you will find that he is well aware of this matter, and that I agreed to teach his Defense class on the explicit condition that no inquiry be made into my -"

What exactly was Dumbledore aware of? Merely that 'Quirrell' may have travelled without a visa (I guess this is illegal), or that he was an impostor? If the latter, why would Dumbledore hire him?

But if Dumbledore wasn't aware that Quirrell is an impostor, then Quirrell has made at least one foolish slip. During the interrogation, Scrimgeour says

"Born the 26th of September, 1955, to Quondia Quirrell, of an acknowledged tryst with Lirinus Lumblung..." intoned the Auror. "Sorted into Ravenclaw...

But way back in Chapter 16, Quirrell says

Yes, I was in Slytherin and I am offering to formulate a cunning plot on your behalf, if that is what it takes to accomplish your desire.

My reading of the visa thing was that the Auror made it up on the spot to confirm that Quirrell had no idea of what trips he had taken in the past, and is therefore an impostor. Although I don't understand why Quirrell, if impersonating someone, would fail to look up these simple facts.

Because Q is someone very good at what he is about to teach who does not want to have his identity public. Dumblodore wants a decent teacher - as has been pointed out many times - and is willing to put up with a lot to get him.
Now weather Dumbledore knows the true identity of Q is a different question.

Jumping in time just 6 hours back indicates to me that in the computer that is simulating MoR universe data is kept with 6-hours long cache.

As to Atlantis - they found a way to get out of the box - one level up, and they've left some cheat-codes for people that are still in this simulation. That also explains why some very important figures (like Dumbledore) think MoR runs on stories - somebody outside of simulation changes the simulation accordingnly. Maybe this simulation purpose is to make the best stories?

Also explains why prophecy works for more than 6 hours into the future - because simulation has some invariants, that make for best stories, and seers can well, "see" them, but only for very important events, and only guess ral meaning of these predictions. Hence mysterious prophecies.

It seems possible to me that MoR spells work a bit like the URLs for TvTropes pages. When a new spell is created, it is attached to an arbitrary incantation of the casters choosing. From then on, that incantation recalls that same set of effects no matter who performs it, like entering a URL into TvTropes to retrieve a page that someone else wrote, when just yesterday that URL led to a blank page.

What I want to know is whether Atlantis was the origin of the system or merely the last society to have edit privileges. (Maybe they abused the system and destroyed themselves so whatever's running the simulation brought the banhammer down on the inhabitants of the MoR verse, and thus began the decline of magic?)

I think Hat and Cloak is Lucius Malfoy. First piece of evidence: timing of his first appearance.

Chapter 34: Harry says "Maybe I'll just do what Draco tried with Zabini, and write a letter to Lucius Malfoy and see what he thinks about that."
Chapter 35: Hat and Cloak appears on-screen for the first time, to talk to Zabini.

Second piece of evidence: He says "Lucius Malfoy has taken notice of you, Hermione."

Lucius is evil and has reason to foster distrust of Dumbledore, two points in favor of H&C being him, but his taste in plotting seems to run far more to the political style, manipulating the press, using flattery and favors to gain control, than to weird, secretive manipulation.

I concur that H&C is Lucius Malfoy. It seems very plain if you look at the proximate results instead assuming every character belongs in the cast of Death Note. A plan that requires that many conditionals is bound to fail.

-H&C messes with Hermoine so that she hates Draco: Draco and Hermoine stop being friends.

Not everyone has to be playing Xanatos Roulette. Some people can just use influence and get back solid and predictable returns from their actions. Lucious Malfoy makes good and predictable gains with each of these plans.

66 - SA Part I, key seems to be "Lessson I learned is not to try plotss that would make girl-child friend think I am evil or boy-child friend think I am sstupid," & "You will losse patience long before sseventh year, perhapss before end of thiss one. I sshall plan accordingly."

73-77 - SA more thereof, ends with H&C groundhog attack on Hermione

Now, any of you folks digging up anything from the suggested chapters?

The first thing I noticed is that the list contains the Santa Claus messages and H&C appearances (14, 21, 35, 63, 77). Presumably all chapters that contain strong and deliberate hints at H&C's identity are on the list. I notice that neither the chapter where Remus talks about Sirius and Peter, nor the chapter where a prisoner is mumbling "I'm not serious [Sirius]" are on the list, so H&C is unlikely to be Sirius. On the other hand 65 which has Quirrel explain that the port key Santa Claus sent had a misleading description attached is not on the list either, so that may not be definite.

Hat-and-Cloak is Voldemort but not Quirrell. When in Quirrell, Voldemort has a whole (probably quite powerful!) brain to run his computation on. Outside of Quirrell, he relies only on what computation he can do purely as a 'ghost', or as magic, or whatever. Hat-and-Cloak is thusly disguised because Voldemort lacks a body. Or maybe Voldemort possesses someone else, who isn't as smart as Quirrell, and is proportionally dumber and more prone to mistakes. Quirrell is zombie while Voldemort's away because Voldemort set it up that way. Don't want your robot walking away without you.

Part of the groundhog-day attack involved setting up a trigger in Hermione, that when she can attack Malfoy, she should try to kill him. This explains her behaviour in the battle, and her apparent behaviour in the duel.

Hat-and-Cloak is a player in this story. Players in this story are clever and powerful. A sensible way of resolving this apparent contradiction is to postulate some form of disability or restriction applying to Hat-and-Cloak. Then all you need is Conservation of Characters.

It would simply be bad writing to set up a mysterious and malevolent figure like Hat and Cloak and then reveal him as one of the story's established villains. It's redundant, a wasted move, to reveal that the villain was secretly a villain. It drains tension from the story to reveal that the heroes were only facing one opponent, not two. I would rule out the possibility just by assuming a competent author.

A point in favor of Hat and Cloak being Grindelwald: the playing card he chose to represent Dumbledore was the King of Hearts. ♥

What evidence is there that H&C isn't just Quirrell wrapped in an illusion?

There's no need for Hermione to have cast the lethal hex. She wins the duel, then the real perpetrator stuns both of them, hexes Draco, and then memory charms Hermione into thinking she did it. However, if that's the case, unless the perpetrator then used Hermione's wand to cast the hex, checking what spells her wand had cast would reveal something fishy.

If Voldemort's possession ability worked like that, though, why wouldn't he just use Quirrel's body for that? You'd think that he would make sure to use his smartest host for anything requiring puzzle solving or careful manipulation.

Perhaps Voldemort doesn't want Quirrell to know certain going plans? Perhaps Voldemort thinks not involving Quirrell is the most effective method of convincing targets that someone other than Quirrell is doing this? Perhaps Hat-and-Cloak's secrecy is to normal people what Quirrell's brilliance is to Harry (convincing), and Voldemort thinks or know that Quirrell can't pull off being H-&-C properly? Perhaps Quirrell is monitored in some way that he can't safely or nonsuspiciously avoid (I can believe Dumbledore setting up some such thing) and so Voldemort does just enough to fly under the "openly hostile" rader, using Hat-and-Cloak to strike the tinder as it were?

I don't know, but I suspect that if my claim is the case, the answer to your question is a reason the story itself does not reveal.

You'd think that he would make sure to use his smartest host for anything requiring puzzle solving or careful manipulation.

He certainly does the lion's share. Perhaps Hat-and-Cloak only handles less challenging or less dangerous-to-fail situations.

When H&C drops the disguise, Hermoine recognizes him/her. I don't think it is particularly likely that ghost-Voldemort looks anything like any picture of him from a history book. So how would Hermoine recognize him?

I quite doubt Lucius is upset with Harry at the moment. He's not stupid, and Harry is not to blame for what happened to his son.

And I'm quite confident Quirrell is not H&C, as the Defense Professor would have been considerably better at brain-washing Hermione. Besides, Harry will know that Hermione truly going dark is far more unlikely than interference via mind-magic or blackmail. He is going to stay on her side and investigate what happened, and Quirrell would anticipate this and not expect Harry to fall into darkness.

Harry's not to blame, but the person Lucius believes is posing as Harry might well be.

From Lucius's perspective it must seem more likely that Hermione is a cat's paw than that she's actually strong enough to beat Draco fairly. Plus, having a Muggleborn arrested for the attempted murder of another student hurts Dumbledore as well. It would be far from unreasonable for Lucius to leap to conclusions at this point.

He would not have been considerably better at brain-washing Hermione. Others, yes, but not Hermione. Quirrell is Voldemort, the ultimate evil (that we know of). Dumbledore has said that "Evil is that which does not love, and cannot know love without ceasing to be evil," or similar.

Quirrell has already tried to convince Harry that Hermione is making a show of goodness to further her own ends. If he really believes that to some extent, given that he's the ultimate evil, he would have a hard time modeling Hermione's thought process well enough to get it right on the first try.

Eliezer thoroughly deconstructed Dumbledore's (And Gandalf's) view of evil in Lord of the Rationality. "If the Enemy thought that all his foes were moved by desire for power alone - he would guess wrongly, over and over, and the Maker of this Ring would see that, he would know that somewhere he had made a mistake!"

Even if somehow Quirrell was stupid enough to not truly understand non-sociopathic motives, he would not make the obvious mistake of revealing this weakness to Harry. Harry thinks that Quirrell can't comprehend good because that's what Quirrell wants him to think.

And H&C didn't even fail because of a miscalculation about Hermione's altruism. It was a rookie mistake to not use a different appearance than you did with Zabini. Even if you still wanted to look dark and mysterious, you wouldn't pick the exact same disguise you used earlier, just in case.

Finally, H&C's dialogue is highly unquirrellish. "I hoped for better from you, Hermione. Surely such a Ravenclaw as you, the most intelligent Ravenclaw to grace Hogwarts in a generation, knows that appearances can be misleading." Those are not the words of a Dark Lord who doesn't care about your opinion and is about to wipe your memory.

Excellent point, but I hardly think this is a Sauron-level mistake. He may not absolutely fail to consider the actions and thoughts of moral people, but that doesn't mean it doesn't take him a few tries to find what buttons to push on an almost absolutely moral little girl.

Quirrell has to have some weakness, after all, if Harry is to ever beat him, as he presumably will. Why couldn't it be that Quirrell is truly cynical and does truly believe all people act selfishly most of the time? Why couldn't that omake be a foreshadowing of Quirrell's downfall? Quirrell would never have left Mount Doom unguarded, but that doesn't mean he won't make some other, smaller critical mistake.

He might have revealed a weakness to Harry, even as brilliant as he is. He certainly doesn't love Harry, he's certainly not fond of him, but I think he feels a kinship with him, given that Harry houses a piece of Voldemort's mind/soul/whatever. In his effort to turn Harry Dark, he might yet reveal more than he should.

Quirrell doesn't have to be perfect. If he were, then Harry could never defeat him. Just that he never holds the Idiot Ball doesn't mean he doesn't make small, insignificant-seeming mistakes that may haunt him later.

The strongest evidence that H&C is not Quirrell seems to me to be how much more amateurish he is at manipulating people than Quirrell is. I don't believe it would have taken Quirrell dozens of iterations to realize he ought to change his appearance. It probably wouldn't have taken him one.

Yes, but he wouldn't have made obvious slip-ups. H&C came within two words of blurting out "Time travel." No way Quirrel did that, unless he's playing a nth-level game through the fourth wall. (Which I wouldn't put past him at this point, but anyway...)

Eh, by now you know you overthought this. Eliezer could have just meant that he knew there was a trial coming up, or that the song in question mentions the word "hat", or a number of other possibilities.

Seriously, don't limit the hypothesis space to "Either my current theory is exactly right to the letter" or "Eliezer tricked me into thinking the current theory is exactly right to the letter". It's always possible that the other guy just meant something different, no deception involved.

So, possible Wild Guess, but has enough reinforcement that I'm going to throw it out there.

Right now, it seems like Eliezer is pushing to the trial. The chapter implies that Harry has done nothing else of note before Hermione's trial, meaning he will have limited ability to defend her. Without any sort of evidence to raise reasonable doubt, he'd basically have to manipulate the Wizengamot.

... Which, while beyond Harry's ability, is not beyond others. In particular: Quirrellmort.

And if both... then we have two heroes of Slytherin and of Ravenclaw who survived an evil plot, and may well garner sympathy for that plot. And remember, Quirrell promised to make Slytherin and Ravenclaw simultaneously win the House Cup...

Quirrell storming into the trial when the majority of the audience believes him to be the one behind everything sounds quite like this story's style.

The trouble with this theory is that the arc is confirmed to last until chapter 84, and Quirrell being suddenly released from custody would be far too short of a resolution.

I suspect Harry and Co will come up with some sort of last-ditch effort during the trial, leading to some sort of awesome event like the previously suggested Trial-By-Combat (though obviously not that). I suspect Quirrell will play some part in the end, though.

Oh, and I'd like to predict that we find out H&C's identity during this arc.

Chapter 25, Fred and George talking about the Marauder's Map, which is supposed to show all people in Hogwarts by name:

“Still on the fritz,” said George.
“Both, or—”
“Intermittent one ﬁxed itself again. Other one’s same as ever.”

The intermittent one is probably Quirrell, going in and out of zombie mode. But what could be visibly wrong with the other one? My theory is that, unlike all the other dots on the Marauder's Map, one of them doesn't have a name. Who could that be?

I hypothesize that this is Mr. Hat and Cloak. That would mean it's not Quirrell and not anyone the Weasleys would pay much attention to, either. The map must get the names it displays from somewhere, and its reliability in doing so suggests that it gets them from people's minds. My hypothesis is that to appear on the map without a name, you'd have to (a) not be known by name and present appearance to anyone whose mind the map can read, and (b) be an occlumens.

Intermittent one is either people using time-turners, Weasley's don;t know about time-turners, so they think it's showing one person in two places or If it showed two names for the same person, that might be an intermittent bug too, ie Quirrel/Riddle based on who he is at the moment.

Permanent bug might be someone floating in the castle who they know shouldn't be there, perhaps Pettigrew, or Sirius, or someone who should be there but isn't - ie Quirrell being unplottable.

Dumbledore & Snape are known Occlumens, but they show up on the map just fine.

In canon, the bug that Harry saw was Pettigrew on the map but he wasn't actually there in reality.

I don't think either of the glitches are Time-Turners. Time-Turners have (presumably) been used regularly in Hogwarts since the twins arrived, and it's made clear that these glitches are new:

The Map was an extraordinarily powerful artifact, capable of tracking every sentient being on the school grounds, in real time, by name. Almost certainly, it had been created during the original raising of Hogwarts. It was not good that errors were starting to pop up.

Also, bear in mind that the official story is that the time turners are used to treat "spontaneous duplication"; if the map occasionally registers multiple versions of a "spontaneous duplication" sufferer, that would be written off as a feature, not a bug (just not the feature that the twins think it is).

Am I the only one that's worried about Trelawney's prophecy? My vague recollection is that she's a joke of a diviner, but when you get right down to it, the fact that she predicted the same thing for each student in the class isn't such a huge likelihood burden if you consider that they are not necessarily independent events. That is to say, she may well be predicting the death of someone all the students know. Which would suggest a tragic ending to this story, probably, unless it's someone all the students Know-Who.

If this is a murder-mystery arc, then Quirrell is the obligatory Red Herring. He had motive, means and opportunity, and all three were revealed in the first part of 6-part arc. The laws of fiction demand it not be this easy.

Yes, that could be exactly what Eliezer wants us to think, but in the end I think Quirrell being responsible would just be too normal, even if suspicion is temporarily diverted from him by making him a false red herring.

I think the point of this arc is not to leave you wanting for complicated answers to obvious-seeming questions, but simply to keep you on the edge of your seat waiting to see how things play out. It's about knocking down dominoes, not setting them up.

Harry and co. have one untapped potential ally: Lucius Malfoy. If they gave him all their clues, he may be convinced, just as they have been. And he has a powerful motive to find out who really tried to kill his son, even if he goes through with the trial against Hermione to avoid losing face.

The problem is how to approach him. He would not trust Dumbledore (his political enemy), Harry (he believes he is Voldemort and will soon hate him for 'turning' Draco), or Snape or Minerva (Dumbledore's agents).

I nominate Quirrel (to be sent by Harry) - known (or at least publicly displaying himself to be) free of Dumbledore's influence, a powerful Slytherin, and the one who actually saved Draco's life. Lucius would listen to him. Whether Quirrel would want to cooperate is another matter, but he should have some difficulty saying no to Harry and Dumbledore at once.

For Lucius to trust them, some of them might have to volunteer to testify in front of him under Veritaserum that they really believe the theory that Hermione didn't do it. Dumbledore is a known Occlumens, Snape and Quirrel would at least be suspected of being such, Harry told Draco he is so now Lucius knows as well. A weaker character like Minerva would be useless because Lucius could easily believe Dumbledore misled her. This is a problem...

Is Harry's guess at the twins' prank on Rita the correct one, and by corollary, are we supposed to believe that Quirrelmort couldn't come up with a hypothesis that basic, and/or that it had been that easy for the twins to successfully brainwash an adult witch? (And on a meta level: was it worth it to make such a hubbub with such a supremely, well, boring answer?)

Harry leaps to that conclusion before hearing from Dumbledore how difficult they are to create. Even if that was the method, there is still the question of how they managed to accomplish it.

My hypothesis — as of several chapters ago — is that Dumbledore assisted in the Rita prank. He certainly had the motive, since he's playing the game against Lucius and Rita was Lucius's pawn. He also had the means (being incredibly powerful). Why hadn't he acted against her earlier? Because he hadn't been clever enough to think up a good way to get at her without inviting retaliation.

So how did he ever get included in the twins' plan?

Easy: he's in the habit of routinely reading their mind. Evidence for this lies in chapter 63:
"It wasn't that the Headmaster had popped up out of nowhere and was staring at them with a stern expression. Dumbledore was always doing that." There's also weak evidence in chapter 12, where Dumbledore knows Harry wants to reformulate Quidditch (he could know via F&G via Ron). And in chapter 79, where he knows about the map.

So: The twins are walking around thinking about how to implement their plan against Rita, Dumbledore pops up out of nowhere looking for some good gossip, sees their plans, seizes the opportunity. The exact implementation could either be a memory charm (maybe trap her when she shows up at Mary's room looking for gossip about Amelia Bones, Dumbledore's ally), or else Dumbledore could actually pull off the acts Quirrell calls impossible.

I think we're supposed to be able to figure this one out. My mental model of Eliezer says he thinks he's given us more than enough hints, and we have a week to wait despite it being a short, high tension chapter. He makes a big deal out of how Harry only has thirty hours, which isn't enough; he gives us a week, and a lot of information Harry doesn't have.

Who benefits from isolating Harry from both of his friends, and/or making him do something stupid to protect Hermione in front of the most powerful people in the Wizarding World?

Evidence against Quirrell as Hat-and-Cloak: Apart from everything that's already been discussed, he's been trying to strengthen Harry. He chose Draco and Hermione for the armies knowing that the likely outcome would be them getting closer (especially when he set them up against Harry).

Evidence for Quirrell as Hat-and-Cloak: Apart from what has already been discussed, he seemed very interested when Harry mentioned Lucius's threat to set aside everything to protect Draco. And there's that line in the most recent author's note:

anything you think won’t confuse the readers, will.

Which implies we're overthinking this and the obvious answer is the right one.

Quirrell conveniently rescuing Draco after seven hours makes sense if we assume he's also the one who almost killed him.

Evidence I can't sort: Quirrell's admission during interrogation can't have been an accident, and doesn't seem to serve his interests whether he's Hat-and-Cloak or not. If he is, he presumable wants to isolate Harry so he can talk him into stage 2 of the plan - but for that, he needs to be at Hogwarts or otherwise have access to Harry. If he's not Hat-and-Cloak, there's not much reason for him to tie himself up in the Ministry.

Unless he doesn't want Harry to be able to contact him and he wants to have a plausible reason for being unreachable?

I think this makes me update more toward "Quirrell is Hat-and-Cloak," but I'm not convinced.

Nobody has proposed yet that H&C #2 = Snape. The evidence for this hypothesis is that Snape's helping of SPHEW caused a serious escelation of conflict (with Hermoine Granger at the center), and whoever primed Hermoine to attack Draco with the Groundhog Day Attack got her to continue the escelation.

Further evidence for this theory is that H&C is not great at modelling people, and Snape isn't good at mental models of others either.

If you think H&C2 is the same as H&C1 (I do, for conservation-of-detail reasons), Snape is a plausible candidate for competent plotter who isn't Quirrell or Dumbledore. Which isn't to say that there a clear motive in that case either.

This matches research showing that there are "sacred values", like human lives, and "unsacred values", like money. When you try to trade off a sacred value against an unsacred value, subjects express great indignation (sometimes they want to punish the person who made the suggestion).

My favorite anecdote along these lines - though my books are packed at the moment, so no citation for now - comes from a team of researchers who evaluated the effectiveness of a certain project, calculating the cost per life saved, and recommended to the government that the project be implemented because it was cost-effective. The governmental agency rejected the report because, they said, you couldn't put a dollar value on human life. After rejecting the report, the agency decided not to implement the measure.

Trading off a sacred value (like refraining from torture) against an unsacred value (like dust specks) feels really awful. To merely multiply utilities would be too cold-blooded - it would be following rationality off a cliff...

I can't end without mentioning that there has been some empirical work done on investigating which cognitive features make people libertarians. The main example that comes to mind is Philip Tetlock's investigation of taboo tradeoffs. Roughly, if you present subjects with a dilemma about a hospital administrator who has to choose whether to spend a million dollars on buying a six-year-old child a kidney, or spend the same million dollars on hospital equipment, doctor salaries, et cetera, what you discover is that most subjects, liberal or conservative, want to punish an administrator who even thinks about the question. People who identify as libertarian don't get angry at the administrator for thinking about it. And the first obvious interpretation of an experimental result isn't always the correct one, but sometimes, you know, it is.

I don't think it'll come completely out of the blue. Come to think of it, perhaps the reason they need so many aurors is that they suspect Hermione of being more than she appears? Accusing a muggleborn of beating up your son is shameful, accusing a secret evil double-witch isn't. Maybe they'll accuse her of being an adult in disguise or something.

Well, I don't think it'll come completely out of the blue either, but I don't think predictions are possible at this time. (Should've clarified). I'm sure it'll all make total and perfect sense... In a few chapters.

By the way, EY, if you're reading this: for whatever it's worth, your writing is amazing, and stuff like the theory of potion making and then using acorns to make bright light is one of the best things I've read. Thanks for being awesome

Premise:
I've studied latin for about 5 years, so I'm not going to use gTranslate for Latin :)
my dictionary sounds better for this scope.

Verb:

The verb prodeo [pro-eo] is the best I could think.

the particle pro- means something like in front of, even between (me) and something, or near (me): this last one is peculiar and happens only sometimes.

eo is the most common and even one of the ancient verbs (that's why is defective/irregular) that means simply go.

So when Cicero (Br. 39) said :

prodire in lucem

he probably meant something like

come out from dark in the light.

Other times is used, like in Caesar (Bg):

in proelium prodire

that should sound like

come out and go to the battle.

OT:
(If you need for other occasion for a "incantation" in a more militar situation , a good one could be subject in ablative case+ proelium proditu (prò-e-li-um prò-di-tu), but that's another topic :) )

Even flowers prodent and in a figurative way, even

lacrimae de gaudio prodeunt

(Apuleio)

tears of joy appeared/came out of (him)

but this sense doesn't matter that much for our problem, i guess.

Subject:

Since you don't use "Hat" for the Sorting Hat, but it seems to me that you want to stress the fact that this "entity" is that important because is a Sorter I would guess

Deligitor

would be the best.

Also Eligitor would be nice there is a subtle difference: the last one means "the one who choose what he prefears".
Deligo[de-lego -> de-eligo] means choose what (or who) is more apt to a peculiar aim.

A Cicero's quote:

ex civitate in senatum delecti

meant something like

choosen among the cives/citizens to form the senate(to be senators)

Deligitor is the noun formed by the verb, means "who choose, who looks for the fittest men (or stuff) for a task and choose them for that task"

The spell:
JKR spells are really more naive, but that's not the point: they are not meant to be real Latin, but they are meant to sound like "Ancient powerful spell with complicated and forgotten words", imho.

The best grammatical looking phrase would be:

Deligitor prodi

that means "Chooser, be present"

because the verb is in the imperative mode, second person singular: prod-i.
But that doesn't sound that good, imho.

A more free construction could be

Deligitor prode

That literally means "(the)Chooser has come to be present here."

and could be quite nice (not too far from Latin, not too boring for a fan-fic).

Or dozen of combination of this ones:
deligit[or;-us,-um] prod[i,it,es,

oh! that could be nice also:

deligitor prodeas

is exhortative(or exhorting, i don't know) conjunctive, that simply means:

please, do this or would you mind doing this or it could be perfect/awesome if you bother to do this

that would sound like Chooser, please come here asap , or Sorting hat, come here since we need you

I'll stop here, waiting for some feedback, because otherwise my mind would be lost in this long trip.

There's a subtle joke in chapter 78 that I'm not sure is deliberate or not. While the most obvious thing connected to polyjuice potion and catgirls is what happens to Hermione in The Chamber of Secrets, what Harry does is mix physics and magic in a way that is also connected to catgirls. In some forums devoted to Dungeons and Dragons there's a saying that goes more or less like "Whenever you try to apply physics to magic, God kills a catgirl." I have to wonder if there's a deliberate reference to this.

(To Eliezer: if you're ever worried about the legal status of MoR, parody is the most obvious way to protect yourself under fair use doctrine, and these pokes at canon will be a main part of your case. I suggest not going light on them to the extent possible.)

If Harry does not manage to find the real culprit, then how does he save Hermione from having her wand broken?

Breakout/Direct Attack on the Wizengamot / Malfoy Manor

Transfigure a one-atom line of antimatter through the earth's crust all the way to the Wizengamot or Malfoy Manor, and then a small bubble there. His wand is then touching the item to be transformed, and it will work.

Transfigure a one-atom line of antimatter through the earth's crust all the way to the Wizengamot or Malfoy Manor, and then a small bubble there. His wand is then touching the item to be transformed, and it will work.

Ten points to Slytherin for creativity. Minus ten bajillion points for holy shit, are you suicidal?!

Harry could offer to pay Lucius Malfoy something in restitution. It couldn't just be money or an incredible favor. As the original 'Taboo Tradeoffs' paper mentions, people only get more angry when you try to do that. Harry would need an accurate model of Lucius suspecting him as Harrymort and be able to trade him something that Harrymort would consider sacred.

Trade his invisibility cloak to Lucius for Hermione's freedom. Make sure to play up that it is 1/3rd of the Deathly Hallows and thus something Harrymort considers sacred/invaluable.

Trade Lucius a blood debt from the House of Potter.

Make an unbreakable vow to protect Draco or otherwise help Lucius (or some other ritual).

None of the trades seem particularly smart or likely, but Harry might consider a few of them if he got really desperate. They seem to be of sufficient value to Lucius (or rather, to Harry's model of Lucius' model of Harrymort) to prove that Harry is genuinely sorry and be worth Hermione's life/magic/future.

Stealth - not only he must transfer cloak to Hermione - he must also get Hermione out of court, and she must be in cloak at all times to prevent tracking magic, and Harry must have the cloak with himself, when Dumbledore will want to see it, when tracking magic will stop working (and there's spell that detects if cloak is nearby).

One way to do this - duplicate cloak using time turner for the moment Dumbledore will want to check it.

Scheme:

Harry takes cloak, mokesking pouch, and time turner with himself to the court

Harry waits for Hermione to disappear

Harry puts his mokeskin poach under the table or somewhere and not look at it

Hermione disappears

Dumbledore try to track Hermione and fails - so he checks if cloak is near - it is, so he asks Harry about it - Harry shows cloak to Dumbledore and it's empty

Harry goes back wearing cloak just before the moment Hemrione should disappear, takes the mokeskin poach that he left under the table, somehow makes everybody look elsewhere and put Hermione into his own mokeskin poach which he keeps under the duplicated cloak (may need to use potion or sth that will turn Hermione into animal or thing or sth that he can put into poach - like with Quirrell as a snake).

Harry in the past waits for Dumbledore to check the cloak that Harry in the present has with himself, waits for everybody to get out, and somehow passes the poach back to himself without looking at himself. Harry in the present puts poach into the cloak.

Possible failures - Dumbledore can keep the cloak, making it impossible to hide Hermione after the time turner is used up. I think Dumbledore won't do this - he didn't wanted to keep cloak to himself, he wants Harry to have cloak just in case, and even if he see throught this plot, he can let it slip, because he probably don't want Hermione to have wand snapped. But it's one failure mode.

Also Harry must be prepared to "prove" he didn't used up his TimeTurner, like he did after Azkaban Breaking.

Quirrel can turn Harry instantly and permanently against Dumbledore (edit: though not Wizarding society in general), any day he likes, by telling him that the Philosopher's stone exists and Dumbledore is allowing Flamel to hoard it (and the method for creating more) for himself.

No stronger method is needed. Harry would declare Dumbledore his enemy on the spot.

That could turn him against Dumbledore (and Flamel), but I don't see how it would turn him against Wizarding society. I doubt most wizards give Flamel or the Stone a second thought, if they even know he/it exists.

It's also notable that the revelation of the existence of Nurmengard, which imprisons wizards without using Dementors, did not really turn him any more against Dumbledore or Wizarding society.

That could turn him against Dumbledore (and Flamel), but I don't see how it would turn him against Wizarding society. I doubt most wizards give Flamel or the Stone a second thought, if they even know he/it exists.

Would he? That might make Harry plot against Dumbledore, but it wouldn't incite the hate that Quirrell seems to desire from him.

No hate for people who are deliberately keeping cheap immortality from the world's population? Who are directly responsible for all age-and-disease death in the last eight centuries? I think Harry can muster a little hate where it's really appropriate.

Besides, I'm certain Quirrell doesn't want Harry to create a utopia, and thus wants him in the dark just as much as Dumbledore.

Harry would hate Dumbledore but he wouldn't succeed in getting his hands on the Stone, not if Voldemort can't. So, no utopia.

No hate for people who are deliberately keeping cheap immortality from the world's population?

You are making assumptions about what how much immortality the Philosopher's Stone allows. For all you know it may allow e.g. a maximum of 7 people immortality, be only creatable once per five hundred years, and/or require the heart of an adult dragon per each person given immortality.

Revealing the presence of such a device (not cheap immortality, but rare immortality) might well cause more loss of life in the pursuit of its possession than it would cause otherwise.

Ofcourse Harry would still be furious at Dumbledore for not analyzing the stone in any way he can in attempts to find a way to mass-produce it or atleast its effects.

Least convenient world apples, but I'd bet Dumbledore and Flamel haven't been looking for cheaper ways to create more Stones, because it just isn't their goal. (And they're already in trouble because they have to guard the one stone from Voldemort.) If Harry knew, well, I'd bet his eyes would be ice and his voice would be distant darkness and... er, I mean, he'd go Librarian-poo crazy.

Hating Dumbledore for guarding the stone is no more rational than hating theists for trying to save everyone's souls. The headmaster's heart is in the right place, and while Harry might become extremely frustrated by him he would still seek to show Dumbledore the light, not to destroy him.

I'm puzzled by Harry's sunlight potion. Did it not require a magical ingredient?

Since we are told that there are no magical ingredients in the lesser woods where the battles are fought, and that all the potions in the books that Harry looks through unlock and redistribute magical energy (rather than ostensibly non-magical energy like sunlight), does this mean that Harry discovered a way to brew potions without magical ingredients? I recall no hint that this is possible, and yet no one watching the battle seems to find the potion notable. To be fair, the fundamental potion-making law doesn't explicitly rule out an all-mundane potion ("A potion spends that which is invested in the creation of its ingredients").

I also find it unlikely that Harry invented the potion himself (I believe general potions-theory and the system for deducing the proper arbitrary stirring patterns would have been given a more complete coverage, if that were the case), so it appears that Harry found a suitable potion using Flitwick's recommended resources. But I still don't know whether the "magical ingredient requirement" is absolute (and Harry bypassed it just by, e.g., putting something of his own magic into the potion as a trigger but not as the main ingredient), whether it's a mere conceptual limit that wizards never thought to test, or whether potions with non-magical ingredients exist and are well-known, but are relatively so rare that Harry just didn't happen to run across any in his initial search.

Remember how the professors made a big deal about Harry not discussing his discovery about potions?

Perhaps school manuals are picked to contain only potions with magic ingredients, as a misdirection for people not wise enough (students) to try to figure out the "well-known secret", the same way Harry was at first.

But Harry's potion didn't release a lot of magic, it only released light (note that in the coin example, it was the non-magical coin that furnished the "heat"), so probably Harry used a bit of magic (like in Potions class) to "rearrange" the light without need of magical ingredients.

Alright, let's get this speculation-train started. My first and most obvious thought is this: Hermione beat Draco to a pulp, and Lucius reported it. He was definitely intending to do something, and would have been monitoring his son. The trouble with this theory is that it involved admitting that Hermione beat Draco fair and square. Still, for Dumbledore to cooperate Lucius is probably involved somehow.

Also, there's Professor Quirrell to account for. I find it unlikely his absence in unrelated, especially when he probably knew Lucius would be up to something. And come to think of it, he probably has his own Marauder's Map(we now know they're in play). Hell, come to think of it I wonder who wouldn't make one if they could. Anyways, he probably doesn't want Granger thrown in Azkaban. Perhaps we'll finally get to see him up against Lord Malfoy?

It is highly unlikely that Hermione would agree to the duel considering her reaction to whatever H&C convinced her of, and Draco saw attacking her on the spot as a forced move. So, Hermione declined Draco's duel and Draco attacked her on the spot.

I think Hermione fought it life-or-death and did Draco serious damage.

Edit: Actually she should not have been able to do him serious damage if the wards actually work as they are alleged to work. Maybe she tried to do him serious damage, the wards did... whatever they do and Dumbledore felt compelled to report the attempt? I'm not sure any more.

My first thought is this: Hermione beat Draco to a pulp, and Lucius reported it. He was definitely intending to do something, and would have been monitoring his son.

My own immediate reaction was 'this in no way serves Hermione or Draco's plans, so it must be a third party, and Lucius just stormed out of the battle'. Except how could Lucius know, and what exactly good does prosecuting Hermione do? It's implied he can't be monitoring Draco in real time by his ignorance and the letter-writing, and it also runs afoul of the Hogwarts magical defenses - so what happened, Draco got beaten, crawled to his room, wrote a letter to Lucius, got it delivered, and Lucius roused the law which rushed to arrest Hermione, all in the <~8 hours after the duel? And while Lucius may have influence in the courts and so risks little by this tactic, it makes Draco's reputation hugely worse to basically everyone (either because he looks extremely weak and dependent on his father or because he's attacking an innocent or because he's using outrageously disproportionate retaliation), and I don't see how it helps Lucius or Draco very much. Dumbledore being imprisoned would be one thing, but Hermione?

It's entirely possible that this is entirely natural. Hermione beat Draco badly enough to put him in the Hospital Wing; either he's legitimately near-death, or Lucius blew it out of proportion.

Alternatively, Hermione and Draco actually talked it out and are currently laying a mutual trap to figure out who's using them both as pawns. I like this option, but it's also probably the least likely one.

Sure. It's just... I feel this would violate the idiot-ball rule - Hermione going berserk enough to put Draco in the hospital wing? Yes, she was angry before, but losing control is an idiot-ball thing to do.

I like this option, but it's also probably the least likely one.

Agree. Not sure how such a mutual trap would expose their manipulators either.

It could be an accident - Hermione hits a chandelier with a cutting cures, etc. It's a fight, things like that happen.

Agree. Not sure how such a mutual trap would expose their manipulators either.

Whoever's manipulating them is probably not anticipating a team up. (And if they are, they're beyond the two's ability to deal with anyway, so no point in worrying about that option.) So, Hermione apparently gets taken out of the picture, while Draco is free to investigate what's going on with a manipulator who's moving ahead with his plan.

... Okay, so that was kind of nonsensical since I was deciding what my opinion was while I wrote it. Let's try this again:

Hermione and Draco meet, and actually talk it out. They decide to work together against their mysterious puppetmaster by playing along with the plot, as opposed to completely derailing it and then not knowing who was behind it.

Additionally, to meta-speculate a bit. I think it is more likely that Eliezer would pretend to destroy the relationship between Draco and Hermione that he has been carefully nudging together for many many chapters then to actually destroy the relationship.

Furthermore, if Draco was seriously harmed there is absolutely no way Hermione wouldn't have seen him to Madam Pomfrey. Perhaps it's going to be made to look like Hermione did something unfair, like tried to cast the Killing Curse?

As for the monitoring, it's possible Lucius didn't need to write but also didn't want his son to know how much he knew about what goes on in Hogwarts.

And as to his goal, I suspect getting the twelve-year-old's wand snapped is not his end-game. However, he could definitely get some leverage over Dumbledore if he has a serious case.

Furthermore, if Draco was seriously harmed there is absolutely no way Hermione wouldn't have seen him to Madam Pomfrey

What makes you think she didn't see him to Madam Pomfrey?

Though it's always possible the wards in the castle immediately warn the teachers of a student wounded to the point of danger to life , and that therefore she wouldn't have time to get him to Madam Pomfrey before she or a teacher arrived to the scene.

Furthermore, if Draco was seriously harmed there is absolutely no way Hermione wouldn't have seen him to Madam Pomfrey.

Hermione is a kind, caring person with a strong moral core, a "Milgram resister" who wouldn't even cast a Simple Strike Hex on orders from a teacher. But she's not a pacifist, is she? Perhaps she could be convinced that harming someone, or letting them be harmed, was the right thing to do. Especially if she was brainwashed a bit.

It seems that the popular opinion around here is that Mr. Hat & Cloak is someone, anyone, other than Quirrellmort. I think this is a case of the same kind of thinking that led people to wonder whether Quirrell was Voldemort a lot longer than Eliezer intended.

I think Eliezer probably meant us to know that Quirrell was H&C the very first time he appeared. Quirrell follows after Zabini when he leaves Harry; Zabini says that Quirrell reacted exactly as H&C told him he would. He knew how Quirrell would react because he is Quirrell, and he told Zabini to do what he did specifically so Harry, who Quirrell knew would be around after the ceremony, could hear it and have another reason to distrust Dumbledore.

Eliezer has already dealt with this once. Everyone suppressed their own knowledge of canon and faculties of logic even in the face of nigh-incontrovertible evidence that Quirrell was Voldemort. He expressed his confusion at this in the author's notes, and I believe he vowed to make his blatant hints more blatant in the future.

I think Quirrell being H&C is even more blatant than Quirrellmort was, and here we are doing the exact same thing. We do it because we love the story and want to preserve as many surprises as we can for as long as possible. We want to wait, wait, wait for a bigger payoff later.

I think Eliezer is likely to be silently rolling his eyes at us on this, thinking "There they go again!" and chuckling quietly to himself. But I know that if he is, he's darn well going to let us figure it out for ourselves this time, rather than once again holding our hands as we step gingerly to conclusions to which he meant us to leap.

Ha! Or maybe Eliezer has been rolling his eyes at us (or, rather, y'all), and gave us a blatant hint with the contrast of competent Quirrell interrogating sneaky Snape and less experienced H&C working on naive Hermione. I think you're just clinging to your one beautiful idea, instead of examining other possibilities - like, say, H&C is taking instructions from Quirrell, maybe?

I think Eliezer probably meant us to know that Quirrell was H&C the very first time he appeared.

I disagree with this at least as strongly as you believe it. I'm pretty sure he meant Hat and Cloak to be a giant question mark. Hence the elaborate descriptions of the broad hat, the dark mist, and the gender-concealing cloak, all drawing your attention to the mystery of his identity. There have been hints, but they don't all point in the same direction the way they do for Quirrell and Voldemort. Some are red herrings. I conclude that we're not meant to be certain of who he is. We're meant to wonder and doubt.

I'm not sure why almost everyone assumes that the first and the second H&C is the same person. Is there any reason to think so, beside their appearance?

Same appearance is a clue to the two H&C-s being related, but not necessarily to identity. For example, a hat and a cloak may be a uniform in a secret society, to be worn in special circumstances. Or, maybe two of them were friends and did pranks like that in their youth. Or, one of them saw the other do this trick once long ago, was impressed, and remembered it. Etc etc.

What I'm leading to is the possibility of the first H&C being Quirrell, and the second being Lucius.

Update March 12: He's reading HPMoR, thanks presumably to the 7+ fan reviews from LWers, tvtropers, and whatever you call an xkcd fan. Still no fan reviews for Luminosity or Hamlet and the Philosopher's Stone.

Damien Walter reviews sci-fi and fantasy for The Guardian.He's looking for weird, self-published online fiction to read over the next month, and he'll review the best ones he finds. He's just asked people to recommend stories in the comments to his latest article. If you want to see Methods of Rationality, Luminosity, or my Hamlet and the Philosopher's Stone reviewed in a respected newspaper (there is precedent!), please consider heading over there and posting a short review (one link per comment, you can comment more than once). Each of the three is a hard sell even by online fantasy standards, and I imagine it would help if a disinterested party vouched for them.

(Can't find a good place to insert my entire current edifice of theory elsewhere, so I'll put it as a top level comment.)

Quirrell is Voldemort is Mr. Hat and Cloak. Quirrell's ultimate goal is driving Harry permanently into his Dark Side, so as to be another Voldemort, either to rule alongside the real Voldie or to be led by the real Voldie.

Quirrell's first attempt at driving Harry over to his Dark Side was with the Dementor in the Humanism sequence. He would have succeeded, had Hermione not been there to bring him out of it. So from Quirrell's point of view, Hermione is Harry's anchor to his good side.

So then it makes perfect sense for all the events of Self Actualization and this new sequence to be Quirrel/Voldie/H&C's handiwork. Quirrell helped SPHEW win that last battle in Chapter 74 so as to paint a larger target on Hermione. When Harry came to him with his plan for that battle, he just laughed, because Harry had unknowingly come to him with a brilliant plan to further Quirrell's own goals for Hermione's doom. He poisoned Hermione against Draco (which was difficult, because Quirrell is pure evil and Hermione is pure good and he can't understand her) so as to provoke House Malfoy further.

Now Hermione is in deep trouble, just as Quirrell intended. All that remains is for something unspeakably awful to happen to her soon, which, Quirrell believes, will help do to Harry what the Dementor almost did in January.

I'd like to point out that after Azkaban, when Quirrell tries to talk Harry into his next plot, Harry refuses by citing what Hermione and Draco would say. Quirrell sits there and thinks for a really long time, and asks if Harry really cares about what they think. My guess is that right then and there is when Quirrell decides to take them out.

Why, in this theory, did Voldemort abandon his quite successful campaign, become the lame Quirrel, and begin fiercely criticizing his former self and attempting to reform magical Britain's children into tools that would defeat his former self?

My own (admittedly somewhat romantic) hypothesis is that Quirrelmort is trying to correct his past mistakes.

Recall the conversation that Dumbledore has with Harry regarding escalation and proportional response. Dumbledore tells Harry that the Light cannot, must not win every battle, because some victories come at too high a price. Harry, on the other hand, believes that the ends justify the means, and that it's all just a matter of thinking up a sufficiently clever solution. Without Dumbledore's intervention, he would've escalated the SPHEW-bully conflict to the point where it engulfs all of Magical Britain, and quite possibly plunges the Wizarding world into a new dark age of terror.

Does that sound familiar at all ?

My guess is that Voldemort, in his original body, was a bit like Harry. He wanted to optimize the Wizarding society, and in order to do so, he had to take over, and in order to make an omelette, you've got to break a few eggs, and there are people opposing you, and before you know it, you're a Dark Lord and people are skinning your opponents alive in your name. The only option was to fake your own death and start anew... which is exactly what Voldemort did.

He didn't abandon his campaign, he got blown out of his body when he tried to kill Harry Potter. Later on he possessed Quirrell, and as he said himself, "One can never quite disentangle the mind from the body it wears". Perhaps he's imbued with some of Quirrell's own opinions. Quirrell must have been somewhat Voldemort-ish before the possession, if Voldie chose him as a suitable vessel.

Incidentally, when all has he criticized Voldemort? I can think of one time, when he said that Voldie was foolish to wish the story of the dojo to be retold. But if Quirrell's part of the story was really Voldemort, then that was simply a lie; Voldie DIDN'T kill everyone on his first visit to the dojo, but later on, deliberately, to sow fear. At any rate, we shouldn't take Quirrell's opinions of Voldemort at face value, given that, to some extent, they're the same person. "Don't believe everything you read."

And Voldemort isn't training Britain's children to defeat a Dark Lord, he's training them to defeat the Muggles. In MoR, Voldemort actually has a good reason to hate Muggles and Muggleborns: their recklessness with power (nuclear weapons, etc.). In his speech before Christmas he all but stated his belief that there would someday be a climactic battle between wizardkind and the Muggle world, which only a united wizarding world could win. That is his ultimate purpose for Dark Harry: to lead the world (or help Voldie lead the world) against the Muggles.

So basically he accidentally torpedoed his original campaign and his life as Quirrel is just making the best of it? But then why didn't he just restart his original campaign? Quirrel seems quite powerful enough to credibly claim to be Voldemort resurrected and enforce his rule, based on his duel in Azkaban with a top Auror and his general position at Hogwarts.

When Dumbledore tells his closest colleagues that draining the life from a follower over a long period would render Voldemort weak compared to his former power, I'm inclined to believe him. Even if you're not, there's the rather inconvenient periods of near-catatonia to get around. (Unless you think that's an act for some reason?)

Chapter 49: ... the Defense Professor, who was slumped over with a small stream of drool coming out of his slack mouth and puddling on his robes.

Chapter 72: ...and Quirrell, face slack, was taking trembling stabs at his soup using a spoon gripped in a fist.

(Actually, I would expect that to be one of the first things Voldemort modified about himself, if it's at all possible.)

I meant more the problems it presents for intimidation value, but I guess if you've Marked your followers to ensure loyalty and/or obedience regardless, it's just a matter of not spending a lot of time in the public eye, which he'd be doing anyway. It's still pretty undignified, but that doesn't seem to bother Quirrell overmuch, so...

The real question, which I don't believe the duel with Bahry or the Massacre of the Bullies answers, is whether Quirrell could stand up to Dumbledore. If he couldn't - even if he just had significantly less endurance - that would make it pretty hard to claim the mantle of Voldemort.

If disutility of Locke (possibly) doing significantly worse on his SAT outweighs the utility of hundreds (thousands?) of readers getting an HPMOR chapter a day early, release on March 9. Otherwise, release on March 10.

I'm a reader who would not be directly affected by the timing relative to the SAT, and I say, please don't stick to the earlier date on my account. I would feel bad suspecting that other readers, who are taking the SAT, were harmed for my pleasure.

Eh, if on March 11th the guy will have just moved, it'd probably take him significantly more than 2 minutes to just unpack his computer, set up his internet connection (if it has been set up all), etc, etc.

Still, I'd tell him to leave it for the 11th, or even the 12th if that's not possible, rather than distract SAT students on the 9th or 10th. (Not that this relates to me personally, btw, I'm neither an American nor a student). He can leave a small note saying he leaves it for the 12th, if need be.

Hat & Cloak is almost definitely going to play a part in whatever happens to Hermione now. Come to think of it, he/she might have somehow been involved in Draco's injuries. Or might even be the one who arranged for Hermione's arrest, since it isn't obvious how that helps Lucius.

Presumably, Hermione has just been the subject of a Groundhog Day Attack, and is now believing whatever the mysterious figure wants her to believe. Said figure is presumably new to the concept, as he almost slipped several times. So Hermione thinks Draco is plotting something to exploit her mysterious destiny.

I wouldn't say that H&C is necessarily new to the concept of Groundhog Day Attacks. If Quirrell is Voldemort and also H&C, he would not likely have a good mental model of the pure and innocent and good and upright Hermione Granger. It would take him a few tries to find the right levers to push.

But I'm not sure that Hermione isn't simply under the Imperius Curse at this point. When she's fighting Draco, she gives her wand a "mysterious flick" in a very un-Hermione-like feint. I don't know why Eliezer would deliberately place that word "mysterious" there unless he wanted to hint that Hermione isn't fully in control of her faculties.

HP discloses to Q, Lucius's conversation, and also speculates that Dumbledore will kill Draco, making it seem as if Harry did it, to get Lucius to stop his game against Dumbledore and go after Harry.

Q suggests only way to remove cognitive dissonance in others is to kill them

Q talks about ways to stay alive and does not mention Horcruxes, instead leading on to the resurrection stone.

HP shows the Deathly Hallows symbol to Q who seems to have been oblivious of the Hallows till now, same as canon, & unsurprising given his Muggle upbringing. So he knows about the cloak, and now the stone, very likely that he knows about the wand as well

I also find it impossible to believe that Hermione lost to Malfoy, she just beat him fair & square in battle. That certainly sounds like a false memory.

I also find it impossible to believe that Hermione lost to Malfoy, she just beat him fair & square in battle. That certainly sounds like a false memory.

They were pretty evenly matched during the Chapter 78 battle, and Draco was a bit drained from charming all the gloves, so it's by no means impossible that Draco beat Hermoine. I expect if they had 10 duels, each would win at least a few.

But it is true that our only sources regarding the outcome of the duel are Draco and Hermoine's memories along with Quirrell's testimony. If those memories were placed by Hat and Cloak, and if Hat and Cloak is Quirrel, then all of our information about what happened between midnight and 6.33am is based on what Quirrell wants us to know. The only bit that is confirmed by another party is that Draco was indeed at some point unconscious in the trophy room.

Draco is the better duelist at this point. Draco tired himself out by casting all those tough spells someone his age should not even be able to do, let alone do many times in a row. This was pointed out by Quirrel and Madame Bones, which makes it unlikely that it was just Draco rationalizing it.

Hermione is more magically powerful and also more clever, but when it comes to dueling, Draco still probably has the edge.

Maybe Malfoy's first self-defensive instinct was right? Maybe he really had worn himself down by casting all those spells on all those gloves, and that's the only reason he lost. Certainly he thought it was plausible enough that he could beat her that it was worth having a duel as a test.